Watermelon Agua Fresca, Rind and All
Watermelon blended with the pale part of the rind, a squeeze of lime and a few mint leaves. The rind is where most of the citrulline is, and it is the part everyone throws away.
Posted Oct. 29, 2026 · 2 quarts, about 6 glasses
Watermelon gets passed around online as the fruit that does for blood flow what a prescription does. The idea comes from citrulline, an amino acid the body turns into arginine and then into nitric oxide, the molecule that tells blood vessels to relax and open up.
The fruit really does carry citrulline, and more of it sits in the white part of the rind than in the red. A glass of agua fresca will not do what a pill does, and the trials that showed an effect used concentrated supplements, not fruit. But it is a cold, cheap drink that keeps a whole melon from going to waste, and it uses the part that has the most of the stuff people are after.
What you need
| How much | What |
|---|---|
| 6 cups | seedless watermelon, cubed |
| 1 cup | pale green rind, outer skin peeled off, cubed |
| 2 cups | cold water |
| 2 | limes, juiced |
| 1 tbsp | honey, optional |
| 8 to 10 | mint leaves, plus more for serving |
| 1 pinch | salt |
How to make it
- Peel the dark green skin off a wedge of rind with a vegetable peeler and cut the pale part into cubes.
- Blend the watermelon, rind, water, lime juice, mint and salt until smooth, about one minute. Work in two batches if the blender is small.
- Taste, then add the honey only if the melon was not sweet enough.
- Pour through a coarse strainer into a pitcher, pressing on the pulp. Chill at least 30 minutes.
- Stir before serving, since it settles, and pour over ice with a mint leaf.
Cook’s notes
- The rind tastes like cucumber, so the drink stays sweet. Start with a cup and work up to two once you know your melon.
- Skip the strainer if you like it thick. The pulp holds the fiber.
- What the research says: citrulline is real, and small trials of citrulline supplements found modest improvements in blood flow and, in men with mild erection trouble, in firmness. Those trials used doses that would take several pounds of watermelon a day. The fruit is a good drink, not a dose.
- Why this sits in the circulation section: the nitric oxide that citrulline feeds is the same signal that every blood vessel uses to open, including the ones men start worrying about after fifty. A diet that keeps that signal working, with plenty of fruit, vegetables and beans, is the long game for the whole system.
FAQ
Is it safe to eat the rind?
Yes. Pickled watermelon rind is an old Southern staple. Wash the outside of the melon before cutting, and peel off the hard green skin.
How long does it keep?
About three days in the fridge. It separates, so give it a stir.
Can I freeze it?
Pour it into ice cube trays and blend the cubes later for a slush.